@INPROCEEDINGS {5008,
author={N. Costa and A. Cartaxo},
doi={},
booktitle={IEEE Lasers and Electro Optics Society Annual Meeting - LEOS},
title={Novel approach for BER evaluation of DQPSK systems using differential phase Q},
year={2007},
month={October},
volume={MP3},
pages={143-144} 
}